scholarly journals Physiological Response of Pelophylax nigromaculatus Adults to Salinity Exposure

Animals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1698
Author(s):  
Jun-Kyu Park ◽  
Yuno Do
Keyword(s):  
Physiological Response ◽  
High Salinity ◽  
Physiological Responses ◽  
Recovery Period ◽  
Renal Tissue ◽  
Freshwater Ecosystems ◽  
Serum Electrolytes ◽  
Salinity Changes ◽  
Pelophylax Nigromaculatus ◽  
Serum Components

Many freshwater ecosystems are becoming more saline, and amphibians, which have permeable skin, are sensitive to this change. We studied the physiological responses to high salinity and recovery from saline exposure in adult frogs (Pelophylax nigromaculatus). Frogs that experienced severe salinity were exposed to saline conditions for 6 days, while those in the moderate group were exposed to saline conditions for 40 days, followed by a recovery period in freshwater for 20 days. Our data showed that during exposure to saline conditions of severe and moderate groups, serum electrolytes increased, protein concentrations decreased, and creatinine, an indicator of renal function, sharply increased. However, renal tissue sampled after exposure did not show renal dysfunction. In addition, serum components that changed during exposure to salinity returned to their initial values during the recovery period. Thus, adult anurans can be resilient, to some extent, to saline conditions in habitats that experience either rapid or slow salinity changes.

Sallow-skin horseshoe crabs (late juvenile Tachypleus tridentatus) as osmoconformers

2011 ◽  
Vol 92 (3) ◽  
pp. 463-468 ◽  
Author(s):  
Yongyan Liao ◽  
Chang-Po Chen ◽  
Hwey-Lian Hsieh ◽  
Yucheng Cao ◽  
Jiejun Chen
Keyword(s):  
Feeding Rate ◽  
High Salinity ◽  
Recovery Period ◽  
Tachypleus Tridentatus ◽  
Low Salinity ◽  
Salinity Changes ◽  
Wide Range ◽  
Horseshoe Crabs ◽  
Salinity Challenge ◽  
Salinity Seawater

Sallow-skin horseshoe crabs (late juvenile Tachypleus tridentatus) from 30‰ salinity seawater were subjected to salinities ranging from 0‰ to 70‰ at 5‰ intervals for 7 days. They were returned to 30‰ salinity for 3 days for recovery. During this period, the survival rate, feeding rate, and body mass of the horseshoe crabs were measured. The sallow-skin horseshoe crabs survived well at 15‰–60‰ salinity, fed well at 30‰–55‰ salinity, gained mass at 0‰–25‰ salinity, lost mass at 45‰–70‰ salinity, and maintained mass at 30‰–40‰ salinity during salinity challenge. During the recovery period, the dehydrated (mass lost) horseshoe crabs rapidly gained mass, whereas the water-retaining (mass gained) horseshoe crabs rapidly lost mass. These results indicate that the sallow-skin T. tridentatus horseshoe crabs are osmoconformers and can tolerate a wide range of salinity changes, adapting gradually from inshore low salinity to offshore high salinity.

scholarly journals Current extinction rate in European freshwater gastropods greatly exceeds that of the late Cretaceous mass extinction

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Thomas A. Neubauer ◽  
Torsten Hauffe ◽  
Daniele Silvestro ◽  
Jens Schauer ◽  
Dietrich Kadolsky ◽  
...  
Keyword(s):  
Mass Extinction ◽  
Recovery Period ◽  
Freshwater Ecosystems ◽  
Extinction Rate ◽  
Freshwater Gastropods ◽  
Extinction Rates ◽  
Freshwater Biota ◽  
Order Of Magnitude ◽  
To Come ◽  
Mass Extinction Event

AbstractThe Cretaceous–Paleogene mass extinction event 66 million years ago eradicated three quarters of marine and terrestrial species globally. However, previous studies based on vertebrates suggest that freshwater biota were much less affected. Here we assemble a time series of European freshwater gastropod species occurrences and inferred extinction rates covering the past 200 million years. We find that extinction rates increased by more than one order of magnitude during the Cretaceous–Paleogene mass extinction, which resulted in the extinction of 92.5% of all species. The extinction phase lasted 5.4 million years and was followed by a recovery period of 6.9 million years. However, present extinction rates in European freshwater gastropods are three orders of magnitude higher than even these revised estimates for the Cretaceous–Paleogene mass extinction. Our results indicate that, unless substantial conservation effort is directed to freshwater ecosystems, the present extinction crisis will have a severe impact to freshwater biota for millions of years to come.

scholarly journals Transcriptional analysis of the response of C. elegans to ethanol exposure

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Mark G. Sterken ◽  
Marijke H. van Wijk ◽  
Elizabeth C. Quamme ◽  
Joost A. G. Riksen ◽  
Lucinda Carnell ◽  
...  
Keyword(s):  
Gene Expression ◽  
Physiological Response ◽  
Physiological Responses ◽  
Ethanol Exposure ◽  
Transcriptional Analysis ◽  
Transcriptional Responses ◽  
Genetic Pathways ◽  
C Elegans ◽  
Chronic Ethanol Consumption ◽  
Transcriptional Changes

AbstractEthanol-induced transcriptional changes underlie important physiological responses to ethanol that are likely to contribute to the addictive properties of the drug. We examined the transcriptional responses of Caenorhabditis elegans across a timecourse of ethanol exposure, between 30 min and 8 h, to determine what genes and genetic pathways are regulated in response to ethanol in this model. We found that short exposures to ethanol (up to 2 h) induced expression of metabolic enzymes involved in metabolizing ethanol and retinol, while longer exposure (8 h) had much more profound effects on the transcriptome. Several genes that are known to be involved in the physiological response to ethanol, including direct ethanol targets, were regulated at 8 h of exposure. This longer exposure to ethanol also resulted in the regulation of genes involved in cilia function, which is consistent with an important role for the effects of ethanol on cilia in the deleterious effects of chronic ethanol consumption in humans. Finally, we found that food deprivation for an 8-h period induced gene expression changes that were somewhat ameliorated by the presence of ethanol, supporting previous observations that worms can use ethanol as a calorie source.

Spatial and seasonal variability of emergent aquatic insects and nearshore spiders in a subtropical estuary

2019 ◽  
Vol 70 (4) ◽  
pp. 541 ◽  
Author(s):  
Martha J. Zapata ◽  
S. Mažeika P. Sullivan
Keyword(s):  
Aquatic Insects ◽  
High Salinity ◽  
Aquatic Insect ◽  
Freshwater Ecosystems ◽  
Dispersal Ability ◽  
Insect Community ◽  
Insect Communities ◽  
Low Salinity ◽  
Subtropical Estuary ◽  
Adult Aquatic Insects

Variability in the density and distribution of adult aquatic insects is an important factor mediating aquatic-to-terrestrial nutritional subsidies in freshwater ecosystems, yet less is understood about insect-facilitated subsidy dynamics in estuaries. We surveyed emergent (i.e. adult) aquatic insects and nearshore orb-weaving spiders of the families Tetragnathidae and Araneidae in a subtropical estuary of Florida (USA). Emergent insect community composition varied seasonally and spatially; densities were lower at high- than low-salinity sites. At high-salinity sites, emergent insects exhibited lower dispersal ability and a higher prevalence of univoltinism than low- and mid-salinity assemblages. Orb-weaving spider density most strongly tracked emergent insect density rates at low- and mid-salinity sites. Tetragnatha body condition was 96% higher at high-salinity sites than at low-salinity sites. Our findings contribute to our understanding of aquatic insect communities in estuarine ecosystems and indicate that aquatic insects may provide important nutritional subsidies to riparian consumers despite their depressed abundance and diversity compared with freshwater ecosystems.

scholarly journals Influencing the physiology and decisions of groups: Physiological linkage during group decision-making

2019 ◽  
Vol 24 (1) ◽  
pp. 145-159
Author(s):  
Katherine R. Thorson ◽  
Oana D. Dumitru ◽  
Wendy Berry Mendes ◽  
Tessa V. West
Keyword(s):  
Decision Making ◽  
Group Decision Making ◽  
Physiological Response ◽  
Group Decision ◽  
Physiological Responses ◽  
High Status ◽  
Group Members ◽  
Physiological Linkage ◽  
To Come ◽  
Middle Status

Many of the most important decisions in our society are made within groups, yet we know little about how the physiological responses of group members predict the decisions that groups make. In the current work, we examine whether physiological linkage from “senders” to “receivers”—which occurs when a sender’s physiological response predicts a receiver’s physiological response—is associated with senders’ success at persuading the group to make a decision in their favor. We also examine whether experimentally manipulated status—an important predictor of social behavior—is associated with physiological linkage. In groups of 5, we randomly assigned 1 person to be high status, 1 low status, and 3 middle status. Groups completed a collaborative decision-making task that required them to come to a consensus on a decision to hire 1 of 5 firms. Unbeknownst to the 3 middle-status members, high- and low-status members surreptitiously were told to each argue for different firms. We measured cardiac interbeat intervals of all group members throughout the decision-making process to assess physiological linkage. We found that the more receivers were physiologically linked to senders, the more likely groups were to make a decision in favor of the senders. We did not find that people were physiologically linked to their group members as a function of their fellow group members’ status. This work identifies physiological linkage as a novel correlate of persuasion and highlights the need to understand the relationship between group members’ physiological responses during group decision-making.

Effects of daytime melatonin infusion in young adults

1998 ◽  
Vol 275 (1) ◽  
pp. E19-E26
Author(s):  
Cameron J. Van Den Heuvel ◽  
David J. Kennaway ◽  
Drew Dawson
Keyword(s):  
Young Adults ◽  
Physiological Response ◽  
Physiological Responses ◽  
Bed Rest ◽  
Hand Temperature ◽  
Melatonin Administration ◽  
Significant Attenuation ◽  
Steady State Levels ◽  
Melatonin Production ◽  
Endogenous Melatonin

Daytime oral melatonin typically exerts soporific and thermoregulatory effects; however, it is not clear whether these effects reflect the normal physiological response to endogenous nocturnal melatonin production. We infused melatonin at doses that produced physiological and supraphysiological steady-state levels in 24 young adults during two daytime bed rest protocols. From 1000 to 1630, subjects were infused intravenously with saline or melatonin in counterbalanced order. Each group of eight subjects received melatonin (and saline) infusions at one dose rate: 0.04 μg ⋅ h−1 ⋅ kg body wt−1 (low), 0.08 μg ⋅ h−1 ⋅ kg−1(medium), or 8.0 μg ⋅ h−1 ⋅ kg−1(high). Low and medium melatonin infusions produced plasma and saliva levels within the normal nocturnal range observed in young adults. These levels were not associated with any changes in rectal, hand, forehead, or tympanic temperatures or with subjective sleepiness. High melatonin produced supraphysiological plasma and saliva levels and was associated with a significant attenuation in the daytime increase in rectal temperature, significantly increased hand temperature, and greater sleepiness. It is not yet clear whether the thermoregulatory and soporific effects of daytime supraphysiological melatonin administration are equivalent to the physiological responses to endogenous melatonin.

scholarly journals   Effects of exogenous proline and trehalose on physiological responses in rice seedlings during salt-stress and after recovery

2012 ◽  
Vol 58 (No. 7) ◽  
pp. 309-315 ◽  
Author(s):  
N. Nounjan ◽  
P. Theerakulpisut
Keyword(s):  
Antioxidant Enzymes ◽  
Salt Stress ◽  
Physiological Responses ◽  
Recovery Period ◽  
Growth Enhancement ◽  
Salt Tolerant ◽  
Rice Seedlings ◽  
Growth Recovery ◽  
Growth Increase ◽  
High Level

Two osmoprotectants (proline &ndash; Pro; trehalose &ndash; Tre) were exogenously supplied to seedlings of rice cvs. Pokkali (PK &ndash; salt-tolerant) and Khao Dawk Mali 105 (KDML105 &ndash; salt-sensitive) to investigate their effects on plants exposed to 200 mmol/L NaCl for 6 days and 5 days after recovery from stress. The reduction of growth, increase in Na<sup>+</sup> to K<sup>+</sup> ratio, high level of hydrogen peroxide (H<sub>2</sub>O<sub>2</sub>) content, enhanced activity of antioxidant enzymes (superoxide dismutase &ndash; SOD, peroxidase &ndash; POX, catalase &ndash; CAT and ascorbate peroxidase &ndash; APX) were observed in both rice cultivars under NaCl treatments. Exogenous Pro and Tre supplement to NaCl-stressed plants did not mitigate the reduction of growth during salt-stress. Nevertheless, during recovery plants previously supplied with Tre showed markedly higher percentage of growth recovery than those treated with NaCl alone or supplied with Pro. The beneficial effect of Tre on growth recovery was clearly demonstrated in KDML105 in which growth enhancement was related to reduction in Na<sup>+</sup> to K<sup>+</sup> ratio. Exogenous Pro was able to reduce H<sub>2</sub>O<sub>2</sub> in both cultivars during salt stress whereas Tre could reduce it only in KDML105. Exogenous Tre did not enhance any antioxidant enzymes during stress but enhanced APX activity in KDML105 during recovery. Exogenous Pro enhanced the activity of APX in PK, and POX, CAT and APX in KDML105 during both stress and recovery period. &nbsp; &nbsp;

Simultaneous measurement of intracellular pH and Ca2+ using the fluorescence of SNARF-1 and fura-2

1991 ◽  
Vol 260 (2) ◽  
pp. C297-C307 ◽  
Author(s):  
R. Martinez-Zaguilan ◽  
G. M. Martinez ◽  
F. Lattanzio ◽  
R. J. Gillies
Keyword(s):  
Intracellular Ph ◽  
Simultaneous Measurement ◽  
Physiological Response ◽  
Second Messengers ◽  
Physiological Responses ◽  
High Time Resolution ◽  
Experimental Conditions ◽  
Fura 2 ◽  
Fluorescence Characteristics

Upon cell stimulation with hormones and other mitogens, a variety of biochemical and physiological responses occur within the first few minutes. Changes in both intracellular pH (pHin) and intracellular Ca2+ concentration ([Ca2+]in) are prominent and play a major role in the signal transduction mechanism leading to the physiological response, i.e., secretion, neurotransmission, proliferation, or differentiation. However, it is not clear whether these ions work independently in the activation pathway leading to a particular physiological response. The fluorescence characteristics of most Ca2+ indicators are pH sensitive, and quantitative estimates of [Ca2+]in cannot be made without knowledge of pHin. Thus it is desirable to have a technique to simultaneously monitor these two ions with relatively high time resolution. Here we have developed experimental conditions that allow us to use optimum emission conditions for a pH fluorescent indicator SNARF-1 and optimum excitation conditions for the Ca2+ indicator fura-2. The fluorescence spectra of these compounds are sufficiently different to allow simultaneous measurement of pH and Ca2+ both in vitro and in situ. We have observed simultaneous changes in both pHin and [Ca2+]in in BALB/c 3T3 cells on treatment with the nonfluorescent Ca2+ ionophore 4-bromo-A23187. This temporal relationship between pHin and Ca2+ gives further credence to the interrelationship between these two second messengers in the expression of physiological responses.

scholarly journals Is erythrocyte size a strategy to avoid hypoxia in Wiegmann’s Torquate Lizards (Sceloporus torquatus)? Field evidence

2015 ◽  
Vol 93 (5) ◽  
pp. 377-382 ◽  
Author(s):  
Juan C. González-Morales ◽  
Erendira Quintana ◽  
Hector Díaz-Albiter ◽  
Palestina Guevara-Fiore ◽  
Victor Fajardo
Keyword(s):  
Physiological Response ◽  
Hematological Parameters ◽  
Hemoglobin Concentration ◽  
Mean Corpuscular Hemoglobin ◽  
Mean Corpuscular Hemoglobin Concentration ◽  
Corpuscular Hemoglobin ◽  
Serum Electrolytes ◽  
Blood Samples ◽  
Field Evidence ◽  
Different Altitudes

This study examined changes in certain hematological parameters in a reptilian model naturally exposed to altitude-associated hypoxia. Four populations of the Mexican lizard Sceloporus torquatus Wiegmann, 1828 (Wiegmann’s Torquate Lizard) from different altitudes were sampled to evaluate erythrocyte count (Erc), hematocrit (Hct), mean corpuscular hemoglobin concentration (MCHC), and erythrocyte size (Ers). Blood was also assayed to determine hemoglobin ([Hb]), glucose, lactate, and electrolyte concentrations. Erc was performed using a Neubauer hemocytometer. Hct was calculated as percentage of packed cell volume by centrifuging blood samples. [Hb] was determined using a Bausch and Lomb Spectronic colorimeter. MCHC was calculated with the formula 100 × [Hb]/Hct. Ers was calculated from blood smear microphotographs analyzed with the Sigma Scan Pro software. Values of serum electrolytes (sodium (Na+), potassium (K+), and calcium (Ca2+)), pH, glucose, and lactate from blood samples were obtained through a blood electrolyte analyzer. Highland populations of S. torquatus exhibited a significant increase in Erc, Hct, Ers, and [Hb]. In contrast, MCHC showed no correlation with altitude. Additionally, significant differences in lactate, Na+, K+, and Ca2+ were observed in highland populations. In general, we found that most hematological parameters were significantly different among lizard populations from different altitudes. This is the first study to report changes in Ers in relation to altitude, which could be a physiological response to hypoxia.

scholarly journals Ventilatory frequency as a measure of the response of tammar wallabies (Macropus eugenii) to the odour of potential predators

2010 ◽  
Vol 58 (1) ◽  
pp. 16 ◽  
Author(s):  
Valentina S. A. Mella ◽  
Christine E. Cooper ◽  
Stephen J. J. F. Davies
Keyword(s):  
Physiological Response ◽  
Physiological Responses ◽  
Tammar Wallaby ◽  
Olfactory Cues ◽  
Initial Reaction ◽  
Macropus Eugenii ◽  
Long Period ◽  
Ventilatory Frequency ◽  
Introduced Predators ◽  
Over Time

This study uses changes in ventilatory frequency to quantify the physiological response of an Australian terrestrial herbivore, the tammar wallaby (Macropus eugenii), to olfactory cues suggesting the presence of potential predators. Ventilatory frequency proved to be a quantifiable measure to assess the response of this macropod marsupial to olfactory cues. Ventilatory frequency increased from mean resting levels of 45 ± 5.1 breaths min–1 to 137 ± 11.2 breaths min–1 during the first minute of exposure to all odours. These physiological responses diminished over time, with ventilatory frequency in the first minute after introduction of the scents greater than that during the subsequent four, suggesting that the initial reaction was due to disturbance and was investigative in nature. However, the ratio of ventilatory frequency in the remaining 4 min after introduction of the odours compared with before was greater for fox (3.58 ± 0.918) and cat (2.44 ± 0.272) odours than for snake (2.27 ± 0.370), distilled water (1.81 ± 0.463) and quoll (1.71 ± 0.245) odours, suggesting that fox and cat odour provoked a greater response. However, the wallabies’ response to the odour of these introduced predators and to horse odour (2.40 ± 0.492) did not differ. Our study indicates that a long period of co-history with particular predators is not a prerequisite for detection of potentially threatening species. We do not find any support for the hypothesis that an inability to interpret olfactory cues to detect and respond to potential predation by introduced predators is responsible for the decline of these macropod marsupials.

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